1. Field of the Invention
The present invention relates in general to improved packaging methods and materials. More particularly, the present invention relates to a thermolaminated specialty package grade film for receiving a blister portion. Specifically, a preferred embodiment of the present invention relates to a thermolaminated multilayered film comprising, a layer of an amorphous polyester, a layer of a polyester, and an adhesive layer wherein the amorphous polyester layer can be heat sealed or RF induced to a blister portion molded from a formable polyester.
2. Discussion of the Related Art
Product packaging and containers often form an essential element of the marketability of a commercial product. Improved packaging of a product can increase the sales appeal of a packaged product, as well as increase or decrease the cost of a commercial product. For several years, a variety of plastics have been utilized to develop packaging. In more recent times, thermoformed plastic packaging has become extremely popular for a variety of applications. For instance, two piece thermoformed blister packages such as “clamshell packages” are readily used to package a wide variety of materials including tools, toys and other products. The clamshell package generally includes two or more plastic members which are held together at their periphery by mechanical structures such as ridges, by glue, by the use of a solvent, or by a heat seal. Clamshell packages may also be formed from a single sheet of material. In most applications, both the cover and container are thermoformed in the single sheet separated from one another by a fold or hinge. When the sheet is folded over onto itself, the cover and container are brought into engagement so as to form a complete package.
While the existing clamshell packaging is useful in some applications, most are designed for a single use, wherein the container is intended to be thrown away once it has been used. While this is suitable for certain applications, the existing thermoformed clamshell packaging does not, in most instances, provide a reusable storage medium wherein a permanent storage container is utilized. Furthermore, in most cases, these clamshell packages provide a clear shell, wherein graphical inserts may be placed inside freely or glued to one portion of the packaging. The existing clam shell packaging, however, does not allow for a reusable package, wherein a laminated graphical cover may be used instead of the loose insert.
One representative area in which thermoformed packaging has been expanded, is in the manufacture and sale of entertainment and/or digital materials such as cases for videos, CDs, CD ROMs and DVDs. Sales and distribution of CDs, CD ROMs and DVDs has grown considerably in recent years, and along with this growth have been many attempts to construct reusable storage cases for such discs. The traditional case is the plastic “jewel-box.” This type of CD case is constructed of two clear plastic pieces that are hinged together. The plastic used is typically injection-molded polystyrene, which is a rigid, brittle plastic. In the center of the pieces are elements that serve to mount the CD within the case and to prevent any part of the case from contacting the surface of the CD.
While these jewel-box types of CD cases serve to protect the CD from contact with dirt and impact, they can be easily broken if dropped. The plastic cases increase the weight of the CD package and increase shipping costs, which can become very expensive in the mass production and distribution of compact discs, such as for promotions by computer on-line service companies, or by mail-order music companies. Furthermore, the graphical cover is most often loosely inserted within one of the plastic pieces. Such inserts are easily lost, and do not always provide a nice finished look to the storage case.
Furthermore, the mass production of plastic jewel-box CD cases has raised many environmental concerns, especially since polystyrene can not be easily recycled and its manufacture is potentially environmentally hazardous. Thus, there has been an effort in the industry to construct a CD storage cases and other specialty storage containers that minimizes the use of brittle polystyrene in place of more environmentally safe products. One solution to the jewel box has been to mount a plastic support having a hub for attaching the CD within a cardboard jacket. Examples of such products are shown in U.S. Pat. Nos. 5,419,433 and 5,421,453, both to Harrer et al. While these patents are an improvement over the traditional jewel-box type case, they still require the use of several components to construct, and still require the use of a plastic insert to mount the CD, usually with glue or some other adhesive. As a result, the plastic insert can be easily peeled away and the bond is loosened due to the effects of moisture. Furthermore, the paper cover is prone to peeling and rapid deterioration thereby not allowing for clean, finished look.
The problems in the CD packaging industry is illustrative of a larger problem in the packaging industry as a whole. While blister receiving portions are useful in the packaging industry because they can be formed to receive an infinite amount of materials, there does not currently exist a reasonable cost effective means to affix the blister portion to a laminated cover in a reusable package or container. The use of glue and other adhesives has proved ineffective in mounting the blister portion to the cover. When glues or other adhesives are used, the edges of the blister portion are prone to peeling and are often easily removed from the cover portion such that the package or container is not long lasting or adequate.
Furthermore, in any application, the cost of packaging is a source of tremendous competition such that scrutiny by product manufacturers is often intense. Consequently, packagers are extremely cost sensitive. Packagers are also coming to grips with the ever increasing problems of waste plastic disposal. Plastic packages are coming under sharp criticism because of their relatively short useful life, their relatively long decomposition time, and their growth as a waste product. These problems are in addition to the normal challenges of providing an attractive, useful package for a growing diversity of products. Thus, package manufacturers are being asked to balance manufacturing needs, customers' desires and environmental concerns on a scale never before imagined.
To complicate matters, many materials useful for forming packages and laminating are often unacceptable for one reason or another. For example, polyvinyl chloride (PVC) makes an excellent package as the material is relatively inexpensive, clear, tough, durable and easy to seal shut using a heat sealing process. PVC is often, however, perceived to be environmentally unfriendly. Therefore, there is pressure on manufacturers to use alternative materials. Polyethylene terephthalate (PET), can be used for packaging. PET, while more expensive than PVC, is clear, durable and recyclable. However, PET cannot be easily heat sealed or solvent sealed and this limits its broad applicability.
Finally, while the packaging industry has developed to meet the needs of the largest industries, there remains several smaller market products that require improved reusable packaging to increase the marketability of their products. Such areas as commemorative coin market or souvenir market do not currently have a good variety of alternatives for use in packaging. Several of these niche markets need a reusable storage container wherein a decorative laminated cover could be used to advertise the product while on the shelf.